HVAC module

Abstract

An HVAC module for a vehicle includes an upper airflow from an evaporator having an upper hot branch through a heater core and an upper cold branch that bypasses the heater core. A lower airflow from the evaporator has a lower hot branch through the heater core and a lower cold branch that bypasses the heater core. An upper barrel door is to select an upper blend setting of the upper airflow directed through the upper hot branch and through the upper cold branch. A lower barrel door is to select a lower blend setting of the lower airflow directed through the lower hot branch and through the lower cold branch. The upper hot branch and the lower hot branch are connected to a rear duct connected to an upper blend zone. The upper cold branch feeds the upper blend zone. The lower cold branch feeds the rear duct.

What is claimed is: 
     
       1. An HVAC module for a vehicle, comprising:
 an upper airflow from an evaporator having an upper hot branch through a heater core and an upper cold branch that bypasses the heater core; 
 a lower airflow from the evaporator having a lower hot branch through the heater core and a lower cold branch that bypasses the heater core; 
 an upper barrel door to select an upper blend setting of the upper airflow directed through the upper hot branch and the upper airflow directed through the upper cold branch; 
 a lower barrel door to select a lower blend setting of the lower airflow directed through the lower hot branch and the lower airflow directed through the lower cold branch; 
 an actuator arm connected to a single rotary actuator, the actuator arm rotatable by the single rotary actuator; 
 an upper door lever to rotate the upper barrel door; 
 a lower door lever to rotate the lower barrel door; 
 a flexible kinematic link disposed between the actuator arm and the upper door lever, the actuator arm linked to the upper door lever by the flexible kinematic link; and 
 a rigid kinematic link disposed between the actuator arm and the lower door lever, the actuator arm linked to the lower door lever by the rigid kinematic link;
 wherein the single rotary actuator controls rotation of the upper barrel door via the actuator arm, through the flexible kinematic link to the upper door lever; 
 wherein the single rotary actuator controls rotation of the lower barrel door via the actuator arm, through the rigid kinematic link to the lower door lever; 
 wherein the upper hot branch and the lower hot branch are connected to a rear duct connected to an upper blend zone; 
 wherein the upper barrel door and the lower barrel door are each barrel doors, each having an outer surface in a shape of a slice of a respective hollow cylinder closed on both ends; 
 wherein the upper barrel door and the lower barrel door rotate about a respective axis at a respective center of the respective hollow cylinder; 
 wherein the upper cold branch feeds into the upper blend zone; and 
 wherein the lower cold branch feeds into the rear duct. 
 
 
     
     
       2. The HVAC module as defined in  claim 1  wherein an upper airflow path for the upper airflow is less restrictive than a lower airflow path for the lower airflow. 
     
     
       3. The HVAC module as defined in  claim 2  wherein a first barrel radius of the upper barrel door is larger than a second barrel radius of the lower barrel door. 
     
     
       4. The HVAC module as defined in  claim 2  wherein:
 a first barrel radius of the upper barrel door is equal to a second barrel radius of the lower barrel door; and 
 the lower barrel door is narrower in a left-right vehicle direction than the upper barrel door. 
 
     
     
       5. The HVAC module as defined in  claim 3  wherein the HVAC module has a temperature setpoint with a range of settings from 0 percent module heat to 100 percent module heat. 
     
     
       6. The HVAC module as defined in  claim 5  wherein:
 the upper blend setting ranges from 100 percent upper cold to 100 percent upper hot; 
 100 percent upper cold corresponds to 100 percent of the upper airflow flowing in the upper cold branch and zero percent of the upper airflow flowing in the upper hot branch; 
 100 percent upper hot corresponds to zero percent of the upper airflow flowing in the upper cold branch and 100 percent of the upper airflow flowing in the upper hot branch; 
 100 percent of the upper airflow is divided between the upper cold branch and the upper hot branch by the upper barrel door; 
 the lower blend setting ranges from 100 percent lower cold to 100 percent lower hot; 
 100 percent lower cold corresponds to 100 percent of the lower airflow flowing in the lower cold branch and zero percent of the lower airflow flowing in the lower hot branch; 
 100 percent lower hot corresponds to zero percent of the lower airflow flowing in the lower cold branch and 100 percent of the lower airflow flowing in the lower hot branch; and 
 100 percent of the lower airflow is divided between the lower cold branch and the lower hot branch by the lower barrel door. 
 
     
     
       7. The HVAC module as defined in  claim 6  wherein the upper blend setting remains at 100 percent upper hot, and the lower blend setting accounts for all cool air entering the upper blend zone for all temperature setpoint settings between 100 percent module heat and 90 percent module heat. 
     
     
       8. The HVAC module as defined in  claim 1  wherein the lower cold branch passes under the heater core. 
     
     
       9. The HVAC module as defined in  claim 1  wherein the lower cold branch passes left or right of the heater core wherein left and right refer respectively to negative and positive Y directions in a vehicle coordinate system. 
     
     
       10. The HVAC module as defined in  claim 1  wherein:
 the upper airflow is about 65 percent of a total airflow through the evaporator; and 
 the lower airflow is about 35 percent of the total airflow through the evaporator. 
 
     
     
       11. The HVAC module as defined in  claim 1  wherein a second row vent duct is routed to direct airflow in the second row vent duct from the upper blend zone down and forward of an evaporator feed duct. 
     
     
       12. The HVAC module as defined in  claim 11  wherein a second row floor duct is routed to direct airflow in the second row floor duct from the upper blend zone down and forward of the evaporator feed duct. 
     
     
       13. The HVAC module as defined in  claim 1  wherein the evaporator is to provide cold air and the heater core is to provide hot air.